make test on perl6_args branch

psql -AX -f t/sql/plperl6.sql
1..9
ok 1 - Return an integer from PL/Perl6
ok 2 - Return nothing from PL/Perl6
ok 3 - Return a float from PL/Perl6
ok 4 - Return a varchar from PL/Perl6
ok 5 - Use a single quote in a PL/Perl6 procedure
ok 6 - Calculate the sum of all Fibonacci numbers <= 100
not ok 7 - We can return an argument unchanged
# Failed test 7: "We can return an argument unchanged"
#         have: 0
#         want: 5
not ok 8 - @_[0] is defined when an argument is passed in
# Failed test 8: "@_[0] is defined when an argument is passed in"
#         have: 0
#         want: 1
not ok 9 - PL/Perl sees multiple arguments
# Failed test 9: "PL/Perl sees multiple arguments"
#         have: 0
#         want: 2
# Looks like you failed 3 tests of 9